1、流式查询

1、实体类

package com.wanqi.pojo;

import java.util.Date;

/**
 * @Description TODO
 * @Version 1.0.0
 * @Date 2022/9/12
 * @Author wandaren
 */

public class VoteRecord {
    private int id;
    private String userId;
    private int voteNum;
    private int groupId;
    private boolean status;
    private Date createTime;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }

    public int getVoteNum() {
        return voteNum;
    }

    public void setVoteNum(int voteNum) {
        this.voteNum = voteNum;
    }

    public int getGroupId() {
        return groupId;
    }

    public void setGroupId(int groupId) {
        this.groupId = groupId;
    }

    public boolean isStatus() {
        return status;
    }

    public void setStatus(boolean status) {
        this.status = status;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    @Override
    public String toString() {
        return "VoteRecord{" +
                "id=" + id +
                ", userId='" + userId + '\'' +
                ", voteNum=" + voteNum +
                ", groupId=" + groupId +
                ", status=" + status +
                ", createTime=" + createTime +
                '}';
    }
}

2、mapper

package com.wanqi.mapper;

import com.wanqi.pojo.VoteRecord;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Options;
import org.apache.ibatis.annotations.ResultType;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.cursor.Cursor;
import org.apache.ibatis.mapping.ResultSetType;
import org.apache.ibatis.session.ResultHandler;

import java.util.List;

/**
 * @Description TODO
 * @Version 1.0.0
 * @Date 2022/9/12
 * @Author wandaren
 */
@Mapper
public interface VoteRecordMapper {
//    @Select("select id, user_id as userId, vote_num as voteNum, group_id as groupId, status, create_time as createTime from vote_record")
//    @Options(resultSetType = ResultSetType.FORWARD_ONLY, fetchSize = Integer.MIN_VALUE)
//    @ResultType(VoteRecord.class)
    void all(ResultHandler<VoteRecord> resultHandler);
}

3、mapper配置

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.wanqi.mapper.VoteRecordMapper">

        <select id="all" resultType="com.wanqi.pojo.VoteRecord" resultSetType="FORWARD_ONLY"
                fetchSize="-2147483648">
            select id, user_id as userId, vote_num as voteNum, group_id as groupId, status, create_time as createTime
            from vote_record
        </select>

</mapper>

:::info
this.query.getResultType() == Type.FORWARD_ONLY
this.query.getResultFetchSize() == Integer.MIN_VALUE?
:::

• fetchSize必须设置成-2147483648

4、自定义处理结果集

package com.wanqi.handler;

import com.wanqi.pojo.VoteRecord;
import org.apache.ibatis.session.ResultContext;
import org.apache.ibatis.session.ResultHandler;
import org.springframework.util.ObjectUtils;

import java.util.ArrayList;
import java.util.List;

/**
 * @Description TODO
 * @Version 1.0.0
 * @Date 2022/9/12
 * @Author wandaren
 */
public class V